The cab-side window assembly incorporated "half moon"-shaped inoperable panes which resulted in an overall oblong shape. The platform (underframe) was shared with F-M's 2,000-hp (1,500 kW) end cab road switcher, the FM H-20-44, as was the carbody to some extent. The platform and carbody was also utilized by the H-15-44's successor, the FM H-16-44.
Length was 51 ft (15.54 metres) and weight 250,000 lb (113.4 tonnes). No H-15-44 is thought to exist today.